Reduction-gear mechanism



July 31, "1923.

A, C. STAHL REDUCTION GEAR MECHANISM Filed Dec. 14, 1918 une H1 01Patented July 31., 19230 i 1,463,447 FFICE.

AMBROSE C. STAHL, OJE DETROIT, MICHIGAN.

- REDUCTION-GEAR MECHANISM;

Application filed December 14, 1918. Serial No. 266,84.

To aZZwhomit may concern:

Be it known that I, AMBROSE C. STAHL, a citizen ofthe United States, ofAmerica, residing at Detroit, in the countyflof Wayne and State-ofMichi' an, 'haveginventedJcertain new and usefu' Improvements inReduction-Gear Mechanism-,of which. the following is a specification,reference being had therein to the accompan ing drawings.

The primar object 0 my invention is to provide a re uction gear-mechan1sm that may be advantageouslynsedin the starting and lightingequipment of an automobile,

' particularly where a motor generator is coupled, directly orindirectly, to an engine shaft, so tha txthe' motor maybe used forstarting the. engine or: thestarted, engine used as a source ofpower forenerating electricityfora'lightingsystem. uch is an example of the useof my reduction gear mechanism, which has been constructed to 7 reducespeed when operated in one direction and to establishja directconnection when 0 erated in the opposite direction, therefore, t emechanism besides being a gear reduction constitutes a; two-speedtransmission and may be used in various equipments;

A further object of my invention is to pro-. vide a reduction gearmechanism which is automatic in itschange of operation, there-- byobviating the necessity of-using levers, brake bands and suchdevicesheretofore employed for effecting a change in speed be tween the driveand driven shafts. The device by which this is accomplished isexceedingly compact, simple in construction, inexpensive to manufacture,and as a whole is particularly applicable to any vehicular equi ment. W

y invention Will be hereinafter described and then claimed, andreference will now be had to the drawing, wherein Figure 1 is alongitudinal sectional View of the reduction mechanism;

Fig. 2 is a cross sectional view taken on the line 11-11 of Fig. 1, and

Fig. 3 is a detail sectional view of a modified form of clutch that mayform part of the mechanism. I 7

In the drawing, 1 denotes, by the way of an example, a cylindricalcasing or support in roximity to a' motor generator unit 2, whichincludes a drive shaft 3 extending into the securing means as indicatedat .7. The driving shaft 3 is held against longitudinal movemember andas such will be hereinafter referred to.- i

The outer end of the drive shaft 3 is prov vided with a spiral gear 10having a small spiral angle not to exceed thirty degrees with the axisof the gear shaft and to reduce the cost of manufacture, the spiralteeth may be cut in the periphery of said shaft. This shaft alines witha. driven shaft 11 journaled in a bushing 12 mounted in a bearing 13forming part of a cylindrical housing 14, said housing being fitted onthe end of the casing 1 and held thereon by screws 17 or other fasteningmeans which will permit of the housing being removed in order that easyaccess may be had to the interior of the housing and the casing forassembling and lubricating elements therein.- Longitudinal movement ofthe driven shaft 11 is prevented by a collar 16 mounted on said shaftat-the outer end of the-bearing 13 and by a. spider or cross member 17on the other end of the driven shaft. The spider or cross member 17 hasits ends provided with stub shafts 18 for rotatable spiral gear wheels19 which mesh with the spiral gear 10 of the drive shaft 3.

Adapted to mesh with the spiral gear wheels 19, which together with thespiral gear 10 are somewhat of the planetary type,

are the spiral teeth 20 of a large thrust gear wheel 21, said thrustgear wheel having a clutch hub portion 22 slidable on the drive shaft 3,so that the said thrust gear mayv shift thereon and either establish adriving relation with the gear wheels 19 or become fixed relative to theclutch member 9. The

spiral teeth 20 are on the inner wall of the large thrust'gear 21 and;the periphery of said thrust gear is provided with circumferentiallydisposed teeth 23 adapted to mesh with an internal. rack 24 mounted inthe housing 14 against an annular interior flange 25 carried thereby,said flange being means for holding the clutch gear 21 sta 21 and theinternal rack may be constructed as shown in Fig. 3. In this view theperiphery of the thrust gear 21 is shown as being beveled or conical tofrictionally engage the beveled seat of a ring 27 set in the housing 14.It is therefore apparent that the clutch between the housing 14 and thethrust gear 21 may be of the toothed, conical or frictional type, and

as such serves in this particular instance as terlocked w1th theinternal rack, and assuming that the drive shaft 3 is to start thedriven shaft 11, then the spiral gear 10 imparts movement to the spiralgear wheels 19 which roll on the teeth 20 of the thrust ear 21, byreason of the thrust gear being eld by the internal rack 24 relatlve tothe housing 14. The direction of rotation of the spiral gear wheelsproduces an end thrust of the large gear 21 towards the internal rack,consequently the thrust gear 21 is held stationary causing the spider 17to revolve in the same direction as the drive shaft 3 and thus impart asimilar direction of rotationto the driven shaft 11, but at a reducedspeed for instance a reduction of ten to one as in icated in thedrawing.

When the driven shaft 11 serves as a gasoline engine shaft and isstarted by the drive shaft 3 serving as a motor generator shaft andgains its normal speed, then the speed of the driven shaft 11 will beeater than the drive shaft 3. However, c anging the s iral gear wheels19 from driven-to drive eliaments changes the direction of thrust on thesame, without any change in the direction of the shaft 11. Therefore,the thrust on the gear 21 from the spiral gear wheels 19 becomes changedto opposite direction, from that previously described, causing the largethrust gear 21 to shift inwardly and out of engagement with the internalrack 24 and into engagement with the clutch member of collar 9 thuslocking gears 21 and 10. As soon as this is accomplished there is nogear reduction, and the shaft 3 is drivenvat the same speed as theengine shaft 11. It will be noted however, that when meager gear 21slides out of engagement with the internal rack 24 there is a neutralposition before engagement with the clutch collar 9. While in thisposition, the gear 21 is free to revolve in either direction and floatson the shaft 3 without restraint. However, due to force required toovercome inertia of the gear 21 against rotation suflicient end thrustwill be developed to slide gear axially into engagement with the clutch.It is now a parentthat the inherent tendency of meshmg s lral gears toproduce an end thrust is uti ized to efi'ect a braking action just asthough the periphery! of the thrust ear 2]. were engaged by a manuallyactuate brake band. lso when the shaft 11 is the driving element thethrust of the spiral ears is utilized to efi'ect a clutching actionetween ihllst gear 21 and gear 10, tending to lock em and conse uently Iam able to comp assemble a l the mechanism necessary in the enclosedhousing 14%.

gears. My braking action is automatic,

actly It is thought that the operation and utility of the reduction gearmechanism will be apparent without further description, and

" while in the drawing there is illustrated the preferred embodiments ofmy invention, it is to be understood that the ments are susceptible tosuch variations and modifications as fall withinthe scope-of theappended claim.

What I claim is: I

In a reduction gear mechanism,"a housing, 'a drive shaft extending insaid housing, a driven shaft extending in said housing, a stationaryinternal rackin said housing,

structural elespiral gears supported from said driven:

shaft and bodily movable thereby about the axls of said driven shaft andmeshing with a gear portion of said drive shaft, and means including athrust gear shiftable on said drive shaft adapted to be operativelyinterposed between said spiral gears and said statlonary internal rackto be held stationary relative to said drive shaft by said internal rackto efi'ect a change in speed between said drive and driven shafts.

In testimony whereof I aflix my signature in the presence of twowitnesses.

AMBROSE C. STAHL. Witnesses ANNA M. Donn KARL H. 'lliii

